These "how to scope" videos are EXCELLENT. In the component testing one, you've taught me how (and more importantly WHY) to sweep voltage... and now you're doing the same with frequency. Nothing else I've seen on UA-cam (and I watch A LOT) has really gone into this much detail with practical techniques. Keep up The Great Work. :)
Thank you for your videos. They are some of the best I’ve seen for explaining how to use this equipment. It’s so much better to see someone actually performing these steps. Thanks again.
I purchased a 1951 Philips radio about three week's ago and it had been heavily modified and butchered around the late 60s or early 70s (judging by parts used) . apart from the mess they added they removed one of the IF cans and I am trying to make one and have been doing what you have been in this video when attempting to make it , all of my other British radios are set at 470khz. Anyway a great video that UA-cam needed and a channel well worth subscribing to which I now have. A really excellent no nonsense channel.
The reason the bottom slug does not show a change is due to the bottom slug coil being shorted with 50 ohms across it, the output resistance of your signal generator. Not the correct way to test the transformer. You need to drive the transformer from a high impedance as if it was being driven by the plate of a vacuum tube. Put a 200 kilohm resistor in series with the signal generator signal.
Good video. I would like to know more about how you set up your sweep of that xfmr. So are you putting a square wave into the primary of the xfrmer. Also I didnt see the square wave moving with the frequency change. Im trying to see how to hook up my programmable sig gen and digital scope for alignment of IF in radio. Thanks
my transistor radio kit has IF transformers with one slug only on the top.would I use this same procedure to check their if frequency setting?thanks so much
If I wanted to do this testing and analysis with the IF in the circuit (still mounted to the radio), what considerations would I need to pay attention to in order to get reliable readings? Or, is it even possible to do this with the part in circuit? Excellent and helpful video. Thanks so much for putting this together.
I believe it will work just fine. I've done it numerous times to verify the functionality of the tuning slugs, (the powdered iron rod cores are brittle and sometimes break inside the IF can, and you will think you are tuning it when you really aren't.)
Doesn't the IF transformer assembly also contain two capacitors inside the can, one capacitor connected in parallel with each coil? The diagram at the beginning of the video shows this (C25,C26). Aren't C25 and C26 located inside the IF can?
My understanding is that you are correct. Only the capacitors are adjustable to tune the LC circuits on the primary and secondary of the transformer. The whole point of the IF transformer is to be incredibly selective and only pass the IF frequency across it.
Hey just come across your channel, yay a fellow Brit 😂 you sound close too.. I'm in Doncaster... Excellent content, I am going to start teaching electronics, I'm really quite sick at the moment so won't be soon but I feel like I should do my bit for the future EE and enthusiasts.. I've subbed and will take a look at your content.. 💡You should show how to make a peak detector probe to remove the carrier make the scope even more like an analyzer display 😁.. Fyi on some of my scopes you can turn off a channel and it will still trigger off that channel, or you can use the external trigger input and feed the sync from the generator in there.. I've done similar in the past I've used the external sync from the generator and adjusted the scope so the sweep takes up the whole screen, moved the trace down so you only see the positive half, basically a bode but with the sweep.signal visible, Steve
Bill, I can reproduce your experiment using a scope with a 1M input impedance, but using my Siglent SA with it's 50R input I get nothing like your clear IF response, in fact I can see no peak at all, did you use some kind of pre-amp; any other suggestions? Thanks
It's just a scope probe into my Siglent, no preamp involved. It's been a few months since I did this, but I seem to recall tweaking the scope settings was quite important. Maybe increase the signal generator output level?
@@LockdownElectronics I wonder if the IFT you used was more tightly coupled, I used an old valve IFT where the coils were separated by about an inch, so the tiny output was virtually shorted by the 50R input of the SA. I lashed up a Hi-Z to 50R wideband preamp and now I get curves like the ones' in your video - thanks for replying Bill.
I 10:50 I was a little confused by your scope settings. Ch 1 is showing AC1M at 500mv, and Ch 4 is showing DC1M at 5 volts. Is there that much amplification going on? Thanks for the video.
Your amplitude at 6:00 is different because v/div for the green is 5V and yellow is 0.5v. I'm wondering what your probe compensations are set on the probe and if they match the channel settings?
These "how to scope" videos are EXCELLENT. In the component testing one, you've taught me how (and more importantly WHY) to sweep voltage... and now you're doing the same with frequency. Nothing else I've seen on UA-cam (and I watch A LOT) has really gone into this much detail with practical techniques. Keep up The Great Work. :)
Excellent video, thank you very much!!
Thanks Bill!
Thank you for your videos. They are some of the best I’ve seen for explaining how to use this equipment. It’s so much better to see someone actually performing these steps. Thanks again.
Excellent tutorial. Thanks for giving us another weekly dose of your knowledge.
Thank you for another informative video.
I purchased a 1951 Philips radio about three week's ago and it had been heavily modified and butchered around the late 60s or early 70s (judging by parts used) . apart from the mess they added they removed one of the IF cans and I am trying to make one and have been doing what you have been in this video when attempting to make it , all of my other British radios are set at 470khz. Anyway a great video that UA-cam needed and a channel well worth subscribing to which I now have. A really excellent no nonsense channel.
Foo-king bloody OUTSTANDING ! Thank You.
The reason the bottom slug does not show a change is due to the bottom slug coil being shorted with 50 ohms across it, the output resistance of your signal generator. Not the correct way to test the transformer. You need to drive the transformer from a high impedance as if it was being driven by the plate of a vacuum tube. Put a 200 kilohm resistor in series with the signal generator signal.
A really excellent video on this.....thanks!
Good video. I would like to know more about how you set up your sweep of that xfmr. So are you putting a square wave into the primary of the xfrmer. Also I didnt see the square wave moving with the frequency change. Im trying to see how to hook up my programmable sig gen and digital scope for alignment of IF in radio. Thanks
Thank you
Very good video.
my transistor radio kit has IF transformers with one slug only on the top.would I use this same procedure to check their if frequency setting?thanks so much
Thank you!
Most interesting thanks very much.
If I wanted to do this testing and analysis with the IF in the circuit (still mounted to the radio), what considerations would I need to pay attention to in order to get reliable readings? Or, is it even possible to do this with the part in circuit? Excellent and helpful video. Thanks so much for putting this together.
I believe it will work just fine. I've done it numerous times to verify the functionality of the tuning slugs, (the powdered iron rod cores are brittle and sometimes break inside the IF can, and you will think you are tuning it when you really aren't.)
Doesn't the IF transformer assembly also contain two capacitors inside the can, one capacitor connected in parallel with each coil? The diagram at the beginning of the video shows this (C25,C26). Aren't C25 and C26 located inside the IF can?
Yes, that’s what makes it a tuned LC circuit.
My understanding is that you are correct. Only the capacitors are adjustable to tune the LC circuits on the primary and secondary of the transformer. The whole point of the IF transformer is to be incredibly selective and only pass the IF frequency across it.
Hey just come across your channel, yay a fellow Brit 😂 you sound close too.. I'm in Doncaster... Excellent content, I am going to start teaching electronics, I'm really quite sick at the moment so won't be soon but I feel like I should do my bit for the future EE and enthusiasts.. I've subbed and will take a look at your content.. 💡You should show how to make a peak detector probe to remove the carrier make the scope even more like an analyzer display 😁..
Fyi on some of my scopes you can turn off a channel and it will still trigger off that channel, or you can use the external trigger input and feed the sync from the generator in there..
I've done similar in the past I've used the external sync from the generator and adjusted the scope so the sweep takes up the whole screen, moved the trace down so you only see the positive half, basically a bode but with the sweep.signal visible,
Steve
Thanks. Nice video. And I wish I had some more fancy test gear. My collection of bits is a lot more basic.
Bill, I can reproduce your experiment using a scope with a 1M input impedance, but using my Siglent SA with it's 50R input I get nothing like your clear IF response, in fact I can see no peak at all, did you use some kind of pre-amp; any other suggestions? Thanks
It's just a scope probe into my Siglent, no preamp involved. It's been a few months since I did this, but I seem to recall tweaking the scope settings was quite important. Maybe increase the signal generator output level?
@@LockdownElectronics I wonder if the IFT you used was more tightly coupled, I used an old valve IFT where the coils were separated by about an inch, so the tiny output was virtually shorted by the 50R input of the SA. I lashed up a Hi-Z to 50R wideband preamp and now I get curves like the ones' in your video - thanks for replying Bill.
I 10:50 I was a little confused by your scope settings. Ch 1 is showing AC1M at 500mv, and Ch 4 is showing DC1M at 5 volts. Is there that much amplification going on? Thanks for the video.
Your amplitude at 6:00 is different because v/div for the green is 5V and yellow is 0.5v. I'm wondering what your probe compensations are set on the probe and if they match the channel settings?
Thans ,I am from India
The secondary shouldn't be loaded to simulat real working conditions?
Bill, is it possible for you to do another video similar to this, but looking at the oscillator circuit of a old tube/valve radio?
Wouldn’t using FFT on your scope do same trick?
Subscribed; What more can I say!!
The sweep signal shows both parallel and series resonance because your test setup is incorrect.